Evidence of ecosystem-level adaptation to disturbance in tidal wetlands
Joshua Lerner, Texas A&M University, jlerner@tamu.edu
Rusty A Feagin, Texas A&M University, feaginr@tamu.edu (Presenter)
Thomas P Huff, Texas A&M University, thuff621@gmail.com
Raymond Najjar, Pennsylvania State University, rgn1@psu.edu
Maria Herrmann, Penn State University, mxh367@psu.edu
Jose D. Fuentes, Pennsylvania State University, jdfuentes@psu.edu
Climate change and weather disturbances can dramatically alter the structure and carbon dynamics of tidal wetland ecosystems, including for salt marshes, tidal freshwater marshes, tidal forested swamps, and mangrove forests. These ecosystems play disproportionately large roles in biogeochemical cycling relative to their small areas, yet we know little about how these processes are perturbed by disturbances at regional to continental scales. Through an analysis of 21 years of remotely sensed gross primary production (GPP) for all tidal wetlands of the contiguous United States, we found that these ecosystems engage in a range of adaptive strategies that bias towards either redundancy or efficiency, where bias towards one strategy shifts the relative frequency of perturbation events to maintain a long-term balance between negative and positive perturbations. Of the 22.28% of tidal wetland locations that experienced GPP perturbations greater than ±1 standard deviation from their mean annual cycle, the average perturbation effect size was ±1.1 grams of carbon per m2 per day, and perturbations did not return to their mean annual cycle for at least one month on average. However, negative and positive ecosystem perturbations offset to just +0.03 net gC/m2/day over two decades across the entire United States, suggesting transient ecosystem fluxes sum to reach a long-term steady state where perturbation frequency, magnitude, and duration are interlinked. We also discovered a fundamental relationship between the size and frequency of ecosystem-level carbon fluxes that resembles the Gutenberg-Richter scaling law for earthquake frequency and magnitude. Evidence that there is a consistent, measurable relationship between ecosystem perturbation effect size and return time is theoretically intriguing, given the scarcity of generalizations that can be made about whole ecosystem disturbance responses.
Poster: Poster_Lerner_2-8_59_35.pdf
Associated Project(s):
Poster Location ID: 2-8
Presentation Type: Poster
Session: Poster Session 2
Session Date: Wed (May 10) 5:15-7:15 PM
CCE Program: OBB